TRANSRECTAL ULTRASOUND OF RECTAL TUMORS

Since preoperative staging of rectal tumors is important in planning t reatment, we evaluated transrectal ultrasound (TRUS) staging of rectal neoplasms. In 35 consecutive rectal tumors, we compared TRUS staging results with final pathologic staging. TRUS predicted the degree of tu rner invasion in 19 of 24 patients (79%) and the presence or absence o f lymph node metastasis in 11 of 15 patients (73%). TRUS overestimated the degree of tumor invasion in four patients (17%) and underestimate d invasion in one patient (4%). The depth of tumor invasion was correc tly predicted in all 14 tumors located within 6 cm from the anal verge , but, beyond 6 cm, only 5 of 10 tumors (50%) were staged correctly (p = 0.005). In the group of 11 patients who underwent preoperative radi otherapy, pretreatment TRUS predicted the depth of tumor invasion in o nly six patients (55%) and overestimated tumor invasion in five patien ts (45%), suggesting that nearly half of these tumors were downstaged by radiotherapy. TRUS accurately predicts the degree of tumor invasion , especially in tumors closer to the anal verge, allowing for better t reatment planning in patients with low to middle rectal neoplasms.